[Ben]

Nothing bad will happen if you restore the Android settings on Windows as they use completely different implementations and store their MIDI port/device information in different ways. However, checking the option to restore settings replaces the settings files (clearing out any previous Windows settings). So it's not harmful to restore settings on the initial restore, but if you do it for future ones, that's when you would need to reselect your MIDI devices.

Mike

Thank you Mike,

I will try the Android ==> Windows restore backup soon. 
Another reason why I was playing with that thought: it seems that MP3s are kept in the MobileSheets folder structure even if they're no longer attached to a song.
E.g. when you want to add a new MP3 with the same file name, MS offers the 3 options (replace, rename, use existing file), even if the old MP3 isn't shown in the Audio tab anymore.
Choosing "replace" led to the unexpected result that the initial file was still picked.

Any library restore gets rid of these no-longer-used-files I take it.